# 123  # 计算和比较

# 14  0  # 十进制
# 7   1
# 3   1
# 1   1

# 128 64 32 16 8 4 2 1
# print(2**0)  1
# print(2**1)  1
# print(2**2)  1
# print(2**3)  1
# print(2**4)  1
# print(2**5)  1
# print(2**6)  1
# print(2**7)  1

# num = 7   # 8421   00000111
# print(num.bit_length())  # 求十进制数转换成二进制时所占用的位数
